From: Ryan Davis <ryand-ruby@...>
Date: 2009-07-15T04:36:13+09:00
Subject: Re: Twelve rules of Ruby


On Jul 14, 2009, at 06:16 , David A. Black wrote:

> Not sure why they wrapped weirdly (at least on my screen), but here's
> a correctly-wrapped version, I hope.

Rick did a very good job with some of the philosophical wanking but I  
thought I'd expand a bit on David's list... I have to be a pedant now  
and then :)

(please note, I'm still pre-caffeine... I'm sure I missed something in  
the editing phase)

> 1. Classes are objects.

I prefer to tell my students: EVERYTHING is an object, even classes.

I think it conveys the ontology a bit better.

> 2. Objects don't "have" methods; they have the intelligence to resolve
>   messages by looking for methods along their class/module lookup
>   path.

See #1. Classes, modules, and their anonymous kin _have_ methods.

> 3. Every instance variable you ever see in any Ruby program belongs to
>   whatever object "self" is at that moment, without exception. (Which
>   is one reason that understanding how "self" gets assigned is
>   absolutely vital.)
> 4. A code block is a syntactic construct, not an object.

See #1. EVERYTHING is an object, even blocks.

> 5. Class variables are not class variables, in the sense of belonging
>   to a particular class. They are class hierarchy variables.

I know what you're getting at, but it might be worth having the  
contrast of class instance variables in there so others understand too.

> 6. Inheritance (A < B) is not the same as, and not related to, nesting
>   (A::B).